In addition to the Chronicles of Narnia, C. S. Lewis wrote the philosophical Planet trilogy (also known as the Cosmic Trilogy): Out of the Silent Planet, Perelandra, and That Hideous Strength. These were for adult readers and in the science fiction genre (well, science fantasy, with more than a touch of the Victorian adventure novel) but the overall ethos of Christian philosophy remained the same.
A few years ago I read the book pictured above, about the planet Malacandra (Mars) but for the life of me I can’t remember why this black, human-faced otter has commandeered this poor guy’s boat. There were many strange creatures in it, all described wonderfully, and the main character swooned a lot, as he looks about to do above; that’s all I recall of the plot. Obviously I need to re-read them.